Unfortunately, the nominal 11-12 amp draw is tough to find in a 110VAC-12VDC power supply. Even if a relatively-common 10A supply would work (possible), they are not particularly cheap (~$40+), portable (have an onboard cooling fan), nor ready (still need to add a car socket adapter). For hotel room, probably better to think Handpresso Wild, find an acceptable hot water source.
Thomas, If you check the Handpresso.com website in UK you will see the have a 240v to 12v adapter. 240 v is what they use. So if well hound them
enough, maybe they will make one for 110v. I have a touring bike - Goldwing I plan to use it on, but I also need it for the hotel. I usually go nuts looking
for the closest Starbucks, sometimes it's a mess.
Thomas...I bought a Schumacher Model 1216 power converter at our local Farm and Fleet store and it works great. Only 2 pounds and not very big so very easy to carry. Here is a link to where I bought mine. http://www.farmandfleet.com/products/756193-schumacher-15a-200w-power-converter.html?utm_medium=shoppingengine&utm_source=googlebase&gclid=CjwKEAjw77OhBRCJ7Onfp_HNtwYSJACZqHAWsnyJ40Jz2tyFwyg-_5T0miCgWTbRD67aHHomH2RuwxoCuLDw_wcB#.VC2D5r5vbwQ